Abstract:

The comprehensive influences of different fertilization treatments(CK, N₁, N₂ and N₃) on the characteristics of plant community were analyzed using the six perennial grasslands mixture cultivated for 15 years as materials. The results showed that the richness index of grassland gradually decreased with the increase of fertilization, and fertilization drastically boosted the plant height and aboveground biomass of grassland. The dominant species of cultivated perennial grassland was not obviously changed by fertilization for the first year. In addition, the fertilization in N₂ treatment significantly increased the aboveground biomass and Jaccard diversity index of cultivated perennial grassland(P<0.01), and decreased Whittaker diversity index. Meanwhile, the grassland productivity was improved and the relative stability of community was maintained by fertilization in N₂ treatment.

Key words: Fertilization, Perennial grassland, Mixture sowing, Diversity index

摘要：

以15龄混作禾草草地为对象,研究不同施氮肥量0(CK),75(N₁),150(N₂)和225 kg·hm^-2(N₃)对植物群落特征的综合影响。结果表明:施肥提高牧草高度和地上生物量,降低了植物群落的物种丰富度,但对混作草地主要牧草的优势地位影响不明显。N₂极显著增加了混作草地的产量和Jaccard多样性指数(P<0.01),降低了Whittaker多样性指数,在提升草地生产力的同时,保持了群落的相对稳定性。

关键词: 施肥, 多年生禾草, 混播, 多样性指数